Materials for antifouling advice

[Peter Q]

Hi all,

I am about to start antifouling the underwater areas of my Westerly Discus and would be grateful for some advice on specific products. If I understand the process right I need the following:

anti rust
epoxy filler (I’m guessing if a actually need this I can use what I have from my West System stuff)
epoxy primer
flexible sealant (for the keel root)
primer (tie/bridging primer)
boot top antifouling paint (I’d like a dark blue/navy colour)
antifouling paint

Can anyone give me some specific product recommendations (to use or avoid!). My boat has reinforced bilge keels and is located on the crouch at Essex Marina.

Many thanks.

PQ

 

[Ruffles]

Most people use a LONG mini roller. The sort designed for getting behind radiators. Foam rollers tend to fall apart in my experience.

If you're patching the rust spots on the keels then an angle grinder with a floppy wheel is great. But beware you may not be able to stop! I've used nutrarust in the past. Then epoxied on top.

Suggest blue masking tape for the waterline. And don't leave it on a moment longer than you have to. Removing the gum is a nightmare!

I've never used a primer. Except when I scraped back to the gel coat.

What are you filling?

 

[johnalison]

I went through a stage of using mini-rollers, sold as radiator-rollers but as my boats got bigger I changed to normal 9" rollers, with an extension rod when needed. It doesn't seem to make much difference which head you use but the ones for rough surfaces hold more paint.

Although you can used boot top paint, my current boat came with an enamel boot top which doesn't need repainting each year, just the occasional wipe round.

 

[Tranona]

Not sure why you want epoxy filler unless you have damage to the hull - just using it on cast iron is unlikely to be effective unless you get the keels blasted. Equally don't see a need for epoxy primer. If the boat is already antifouled then you can almost certainly just apply another coat, but best to check that your new is compatible with the old. If in doubt use a primer such as Primocon as a barrier.

Your choice of antifoul will depend on the type of sailing you do and where the boat is kept. Asl around to find out what others find effective. For boot topping you can either buy a dedicated antifoul for this, or use Trilux.

Suggest you look on the websites of the major paint companies (International, Hempel and Epifanes for example) as they have plenty of information to help you choose and apply their products.

 

[JumbleDuck]

Hi all,

I am about to start antifouling the underwater areas of my Westerly Discus and would be grateful for some advice on specific products. If I understand the process right I need the following:

anti rust
epoxy filler (I’m guessing if a actually need this I can use what I have from my West System stuff)
epoxy primer
flexible sealant (for the keel root)
primer (tie/bridging primer)
boot top antifouling paint (I’d like a dark blue/navy colour)
antifouling paint

Can anyone give me some specific product recommendations (to use or avoid!). My boat has reinforced bilge keels and is located on the crouch at Essex Marina.

Many thanks.

PQ

Slobbering on a coat of what's cheap works well for me. A standard roller lasts almost exactly 2.5 litres.

 

[pagoda]

Slobbering on a coat of what's cheap works well for me. A standard roller lasts almost exactly 2.5 litres.

And if it's a tiny bit different in colour , it is vastly easier to do!

 

[Yngmar]

Hi all,

I am about to start antifouling the underwater areas of my Westerly Discus and would be grateful for some advice on specific products. If I understand the process right I need the following:

anti rust
epoxy filler (I’m guessing if a actually need this I can use what I have from my West System stuff)
epoxy primer
flexible sealant (for the keel root)
primer (tie/bridging primer)
boot top antifouling paint (I’d like a dark blue/navy colour)
antifouling paint

Can anyone give me some specific product recommendations (to use or avoid!). My boat has reinforced bilge keels and is located on the crouch at Essex Marina.

Many thanks.

PQ

Some of the stuff I've used in the last few weeks that I can recommend:

Frog tape (green) for masking tape. Stuck on, painted over, left 4 days - came off without residue or tearing and left a razor sharp line. Great stuff.

International Interprotect - 2 part epoxy paint on the keel (mine's lead, but it's suitable for iron as well). Give it a light sanding before painting over. Good, but there's probably cheaper alternatives.

Flag rust converter (Toolstation has a good price on it) to paint over rust (used on engine, not underwater). Works well, shrinks the rust and leaves a black coat for painting over. Not sure how well 2-part epoxy paints will stick to it, probably safe if sanded first.

Sikaflex 291i for the keel seal - roughen with sandpaper after it's cured before painting over. Wear gloves when applying and smoothen with your (gloved) finger. Do not use the soapy water trick to smoothen it, as it can ruin the adhesion.

International Watertite underwater epoxy. Got it to fix some pitting on rudder aluminium parts, but also well suited to fair the keel and fix some nicks and dents on hull and rudder. Excellent stuff and developed for underwater use, but pricey. West system epoxy is okay too if you put protective coats on top of it. They make a great product called Six10 which is a dispenser tube that squeezes out matching amounts of thickened resin and hardener, very easy to use.

Plastic padding gelcoat filler for above the waterline gelcoat damage. Super fast curing (can be sanded in 1 hour but only 10 minutes working time).

Good luck!

 

[TQA]

Use different colour a/f to the current finish.

The chandlery should have rollers for a/f, that is ones that don't fall apart. I use a 9 in on a pole.

Put an extra coat on the bow, waterline and leading edge of the rudder.

 

[simonfraser]

if you have never done this before and you are time limited, forget the boot top

frog tape is excellent +1